Initial results on the application of optical diag-nostic techniques for gas turbine combustion exhaust analysis are described. LII measurements of soot emissions are shown to obtain sensitivities on the order of 10 µg/m³, corresponding to particle concentrations on the order of 10¹⁰ m³. This sensitivity is sufficient to allow analysis of optically "clean" exhaust flows. FTIR absorption and emission measurements are shown to allow measurements of major species, gas temperature, and selected pollutants such as CO at high concen-trations. They are also useful for general exhaust radiative signature analysis. Finally, preliminary results of a quantum-cascade (QC) laser-based sensor for SOx measurements are demonstrated at room-temperature. QC-based sensors are expected to allow in-situ measurements of a variety of pollutant species such as NO, CO, and SO₂ at ppm or lower levels.